Physicians commonly attempt to determine the existence vel non of a patient's muscular response to an applied stimulus, by means of a rubber hammer. Basically, the physician taps a tendon through the skin, and then looks for an involuntary physical response. For example, to test the reaction of the quadricep muscle, the physician will typically ask the patient to first cross his legs while sitting on an examination table. The physician will then tap the quadricep tendon beneath the skin in the vicinity of the knee, and will then look for an involuntary knee-jerk reaction. Upon information and belief, such impulse tapping of this tendon causes the quadricep muscle to contract, causing the involuntary knee-jerk reaction. This technique is also generally used to test the muscular response to a stimulus applied to the achilles tendon, the bicep tendon, the tricep tendon, the brachii radialis, the hamstrings, and the jaw tendons.
Upon information and belief, some physicians have physically placed their finger(s) against the tendon, and have tapped their fingers with the tap hammer. Thus, the impact force transmitted from the hammer to the finger(s) is transmitted through the fingers and the patient's skin to the tendon itself. This technique is believed to permit the physician to "feel" the patient's response, rather than to rely solely on visual observation. In either case, the use of such data has heretofore been limited, and is necessarily subjective. Such data is usually limited to determining whether the patient exhibits a response, or not.
After the stimulus has been applied (i.e., the tendon has been tapped), the impact stimulus must be transmitted along various afferent (sensory) nerves to the spinal cord, must traverse at least one electrochemical synapse to excite the cell bodies of the motor neurons in the cord and to transmit the resulting action potentials from the cord to the muscle membranes along efferent (motor) fibers, must cross the electrochemical neuromuscular junction, and must conduct the resulting action potentials along the muscle membranes to the myofibrils where mechanical contraction occurs. Anything (e.g., disease, injury, etc.) that slows the transmission of neurological conductivity along the foregoing path, will delay the onset of the patient's physical response to the stimulus. This delay is known as "latency". Moreover, the magnitude of the response, or at least the ratio of the response force to the stimulus force, is an indication of the capacity of the conductive path.
Accordingly, it would be generally desirable to quantify and record the data performed by such testing. Such testing is non-invasive, inexpensive and may readily be performed in the physician's office. Moreover, such quantitative data of the parameters of such response (e.g., the period of latency, the response-to-stimulus amplitude ratio, etc.) from tests taken at different times, may possibly be compared to indicate the effectiveness of therapy, or of healing of damaged nerves and tissue. Thus, there is believed to be a definite need for a device for measuring, quantifying and recording certain parameters of such reflex response testing.